Remote controlling apparatus



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March 28, 1939. c. s. SNAVELY 2,152,390

REMOTE CONTROLLING APPARATUS Filed May 14, 1929 '7 SheetsSheet 6 INVENTORZ C. S. sn ve'lr,

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REMOTE CONTROLLING APPARATUS Filed May 14, 1929 7 SheetsSheet 7 Patented Mar. 28, 1939 UNITED STATES PATENT OFFICE REMOTE CONTROLLING Clarence S. Snavely, Pittsburgh, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application May 14, 1929, Serial No. 362,948

72 Claims.

My invention relates to remote controlling 'apparatus, and particularly to'apparatus for controlling tramc governing devices, such as railway switches and signals, from a remote point. In systems of the type described, it is customary to provide apparatus at a control station, such for normally closed line circuit connecting the control station and all remote stations and to deliver both the control codes and the indication codes'to this line circuit and also to provide means" effective when a code is being supplied to the line circuit from any station to prevent the delivery of codes to the line circuit from all other stations. Other features'and advantages of my invention will appear from the appended specification.

I will describe one form of remote controlling apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1' and 1 when placed 'one above the other with Fig. 1 at the top, form a diagrammatic view showing the equipment necessary at the control station for one embodiment of my invention. Fig. 2 is a diagrammatic view showing one form ofremote control. equipment for co-operating with the control station equipment shown in Figs. 1' and 1 and also embodying my invention. Fig. 3 is a. diagrammatic view showing one arrangement of governing devices controlled by the apparatus illustrated in Fig. 2 and also embodying my invention. Fig. 4 is a diagram showing the line circuit between stations and a portion of the apparatus which is at times connected with this line circuit to accomplish line checking and looking in accordance with my invention. Figs. 5 and 6 are detail views showing, in side and end elevation, respectively, one of the switching devices E shown in Fig. l Fig. 7 is a diagrammatic view illustrating the apparatus for providing mechanical 'locking between associated switching-devices E and E shown in Fig. 1'. Figs. 8 and 9 are detail vi'ews showing in front and side elevation, respectively, the stepping contactor P illustrated diagrammatically in Fig. 1.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1', 1 2, 3 and 4, the control station designated as station A is provided with apparatus for controlling tramc governing devices located at a plurality of remote stations,

only two of which are shown in the drawings, 5

and which are designated station B and station X. Each station is provided with coding apparatus designated in general by the reference character A with an exponent corresponding to the location. Each coding apparatus A is at- 10 ranged when actuated to deliver a selected code to a line circuit here shown as made up of line wires l and 2, which line circuit extends to all of the stations. One form of coding apparatus similar to the coding apparatus located at each. 15

of the remote stations in my present invention is disclosed and claimed in an application Serial No. 254,684, filed by me on February 16, 1928, for Railway tramc controlling apparatus, now Patent No. 2,082,428, granted June 1, 1937.

The coding apparatus A located at the control station comprises a motor m' having an armature I and a field 5, which motor operates a plurality of code wheels. In the form here shown the armature 4 of the motor is operatively connected with a gear 9 through a worm 8, a worm wheel 1, and a pinion 8. The gear wheel 9 is fastened to a shaft, indicated diagrammatically at I, and Journalled insuitable bearings not shown in the drawings. of code wheels, each designated by the reference character D with'a distinguishing exponent, and each made up of a disk It provided at its periphery with different combinations of teeth and solidly pinned to a cam l5. shown in the drawings on wheel D but are omitted from the other code wheels for the sake of simplicity. Each code wheel D is normally coupled with the shaft, by means of some friction device, such for example, as is shown in my 40 previous application, Serial No. 254,684, identified above. With thisarrangement, each code wheel and its associated cam would be rotated in response to operation of the motor m if it were not latched in position by the apparatus which I will 45 now describe.

The cam l5 of each code wheel D is controlled by a delivery magnet designated by the reference character (I and provided with an armature I! which controls a pivoted latch i8. The arma- 5o right so that the tip of the latch enters a notch u Shaft III in turn carries a plurality so These teeth are 35 in the cam and prevents the rotation of the code wheel. when the delivery magnet (1 becomes energized, the armature l1 and the latch II are moved to the left, thereby withdrawing the tip of the latch from the notch in the cam l5, and permitting the code wheel to be rotated if the motor m is operated. At the same time a normally closed back contact "-2! controlled by the magnet is opened. It should be pointed out that after the latch II has once been operated to release the cam, the engagement of the latch with the edge of the cam prevents the return of the latch to its normal position until the code wheel has rotated far enough to bring another notch into registration with the latch. Each code wheel D controls a normally closed contact ll in such manner that when the code wheel is rotated the contact is periodically opened in accordance with the teeth in the code wheel. I propose to construct the several code wheels in such manner that each code wheel, when operated, causes a distinctive operation of the associated contact i4 so that a circuit including the contact will then receive a distinctive code element.

It should be pointed out that the coding apparatus here contemplated is intended to control step-by-step selectors of the type known to the art as Gill selectors. Selectors of this type are intended to be operated by codes each made up of a plurality of digits. For example, the selectors may be operated by codes having five digits, the

first of which always contains the same number.

of impulses, which number is one greater than the number of impulses in any other digit of the code. The purpose of this first or clearing digit is to make sure. that the selector always commences its stepping operation from its normal position. The last digit of each code is the operating digit, and always consists of a single im-' pulse. The remaining digits of the code are variable, to produce distinctive codes, and in the present instance each of these digits may consist of any number of impulses from 1 to 5.

In order to create codes. of the type just .described, I propose to furnish each of the code wheels D with teeth which will operate the associated contact to deliver distinctive code elements containing from one to six impulses. By operating selected ones of the code wheels in a selected order, I can therefore produce any desired code.

Each of the code wheels D is controlled by a delivery magnet 11 and each code wheel with its associated magnet and contact will be referred to collectively as' a coding unit, there being as many coding units in the coding apparatus A as are required to provide the different numbers ,of impulses for the several code elements required. Each coding unit is designated by the reference character 9, with a distinguishing exponent. As shown in the drawings, co'de wheel D is provided with three groups of teeth, each having six teeth and the associated cam I 5 is therefore provided with three notches for engagement with the latch l8 of the delivery magnet. The remaining code wheels, having fewer teeth in each group,

may have a greater number of notches in the associated cams, so that a smaller angular movement of the code wheel is necessary between successive lockings by the corresponding delivery magnet.

The unit g is similar to the other units of the coding apparatus, but has no contact M. The

75 am It is provided with a plurality of notches for engagement with the latch ll, so that, if delivery magnet d of this unit is energized while the motor m is operating.'the latch I8 is withdrawn, and a brief interval of time elapses before the latch enters the next notch in the cam. The purpose of unit 0 will be described hereinafter.

The coding apparatus A also comprises a stepping contactor designated by the reference character P and shown diagrammatically on Fig. 1', but illustrated in detail in F188. 8 and 9. It will be seen from the latter drawings, that this stepping contactor comprises a rotatable spider 29 having a plurality of radially extending arms here shown as three in number. The arms of the spider are connected together electrically, and the spider as a whole is arranged to be rotated in a step-by-step fashion by the apparatus which I will now describe. Rigidly attached to the.

spider are two ratchet wheels I! and 3| having their teeth facing in opposite directions. As best shown in Fig. 8, a fixed pawl ll engages wheel 3| and prevents rotation of the spider in a counter-clockwise direction as viewed in this figure. The spider is operated by a magnet F having an armature 48 attached to a link 44 which drives an operating arm 42. The arm 42 is attached to a spindle 41 which is pivoted to allow oscillation of the operating arm. A spring 45' having one end attached to a fixed bracket and the other end attached to link it biases the armature 48 to a position in which a ratchet ll attached to the arm 42 engages the ratchet wheel 30 and locks the spider 29 in position. The arm 42 also carries a pawl H which is pivoted in the tip of the operating arm 42 and is biased by means of a spring 43 to a position in which the tip of the pawl engages the teeth of the ratchet wheel 3|. When the magnet F is energized, armature ll moves to its right-hand position in which it is shown in Fig. 8, thereby swinging armature 42 to the right, withdrawing the ratchet 40 from the teeth of ratchet wheel II, and stepping the pawl I! back one tooth on the ratchet wheel 88. When the magnet F'is next de-energized, spring 4! draws the armature, and hence the operating arm H, to the left, as seen in Fig. 8, thereby rotating the spider 29 by an amount represented by one tooth of the ratchet wheel 3|. It will be noted that at the conclusion of this stroke of the operating arm the ratchet 48 will then engage one tooth of the ratchet wheel 3! so that when the magnet F is de-energized the spider is locked positively against rotation in either direction. It will be seen from the foregoing that if magnet F is alternately energized and de-energized, the spider 29 of the stepping contactor will be rotated one step for each energization and de-energization of the magnet. The contactor P also cornprises a supporting member 32 preferably of insulating material and carrying a plurality of fixed segments, extending radially inward toward the spider 29 'and designated by the reference giaracters 33 to 88, inclusive. The parts of the epping contactor are so proportioned that the interval between the contact segments is equal to the distance through which the spider 28 is stepped by one energization and de-energization of the magnet F. As shown in the drawings the contactor comprises three arms on the spider, and seven fixed segments, one of which is at all times engaged by one of the arms of the spider.

Referring now to Fig. 1", it will be seen that the spider 29 is connected with terminal 13 of a source of energy not shown in the drawings over a front contact of the operating magnet I of the stepping contactor P. When the magnet F is energized, therefore, terminal 13 is connected with a selected one of the fixed segments 88 to 88 of the stepping contactor, depending upon the position of the spider 28. If the spider 28 is in engagement with contact 88 the delivery magnet d of unit g has one terminal connected with terminal B over contact 28-88 of the stepping contactor P, and since the other terminal of. this delivery magnet is always connected with the remaining terminal C of the same source, the delivery magnet will be energized under these conditions. In similar manner, if contact 28-84 of stepping contactor P is closed and if magnet F is energized, the delivery magnet d of unit g is energized. If, however, contact 28-48 of the stepping contactor is closed and if magnet F is energized, the delivery magnet d of coding unit a is energized. If magnet F is energized when the spider 28 of the contactor P engages one of the remaining segments 85, 88, 81 or 88, a selected one of the delivery magnets of the coding units 0 a, a, a, g is energized depending upon the conditions of a series of code selector relays, each designated by the reference character Q with a suitable distinguishing prefix and exponent and shown near the bottom of Fig. 1 The code selecting relays Q are controlled in part by manually operable switching devices which are located at the con trol station and are for convenience grouped in separate panels, one panel for controlling the apparatus located at each remote station. For example, as shown in the drawings, there are two panels, one for station B and one for station X, which stations are illustrated on Fig. 4. Each panel is provided with two manually operable switching devices E and E with prefixes corresponding to the panel and which devices will be described in detail hereinafter. The switching devices E of each panel control a plurality of the code selecting relays Q referred to hereinbefore, and as here shown, four of these code selecting relays are provided for each panel. The purpose of the code selecting relays Q is to connect selected ones of the segments 85, 38, 81 and 38 of the stepping contactor P with selected ones of the delivery magnets d of coding units 0 g, 9 g and a. For convenience, the terminals of the delivery magnets may be brought out to bus bars extending below the series of code selecting relays, and the leads from the segments of the stepping contactor P may be brought out to bus bars extending above the series of code selecting relays. Each code selecting relay has four contacts, permanently connected to the individual bus bars leading to the segments of contactor P, and which are preferably connected with selected ones of the bus bars leading to the delivery magnet of the coding units by means of screw plugs. With this arrangement it is apparent that the connections controlled by any code selecting relay may conveniently be altered by the simple expedient of changing the position of the screw plugs associated therewith.

I will now proceed to describe the switching devices E provided at the control station for the manual control of the coding apparatus A Referring to Figs. 5 and 6, I have illustrated one of these switching devices in detail, and it willbe apparent from an inspection of these figures that the switching device comprises a manually operable lever 88 controlling a rotatable shaft 48. This shaft is constructed of magnetizable material and passes through a magnetizable member oiie of three fixed contacts 88, 84 or 55 depend- J0 ing upon the position of the shaft 88 and lever 48. Also attached to the shaft 88 is a cam. 58 of insulating material which is illustrated most clearly in Fig. 6 and is provided with two outstanding projections 51, the purpose of which will become apparent as the description proceeds.

The cam 58 controls a contact finger 58, which normally engages a fixed contact 88, but which is arranged to be moved at times into engagement with a contact 8|. The contact finger 88 is also controlled by a fixed latch 58 attached to the bracket 85, and provided with a shoulder 58 effective to hold the finger 58 in engagement with contact 8| after the finger has once been moved to its lower position. The armature 82 carries a trigger 88 for at times engaging the latch 58 to release the finger 58, and the armature also carries a contact tip 84 which may be brought into engagement with a similar tip on the extremity of the finger 58.

As shown in the drawings the lever 48 occupies its middle position and contact 5254 of the switching device is closed. The winding 5| is assumed to be de-energized so that the armature occupies its right-hand position as shown in Fig.

5 and the contact finger 58 engages contact 88. If, now, lever 48 is moved in either direction, for example, in such direction that contact 5258 is closed, this movement of the lever causes the cam 58 to depress finger 58 into engagement with contact 8|. It will be noted that when the lever has attained its extreme position so that contact 52-43 is closed, the swell 58 of cam 58 no longer engages the finger 58, but this finger is now held in its depressed position by the latch 58. If now. the winding 5| is energized, the armature 82 is attracted and the trigger 88 engages the latch 59 to release the finger 58. Due to the resiliency of finger 58, the finger tends to return to the position in which it is shown in the drawings, and

' the cam 58 in the position in which it now occupies will permit this movement, but the finger is now held in its depressed position by engagement of the tip 84 on armature 82 with the tip of finger 58. The finger therefore remains in engagement with contact 8| until the winding 5| is de-energized, whereupon the armature 82 is restored to the position in whichit is shown in the drawings by spring 10, and the finger 58 is then released and returns to the position illustrated in Fig. 5. The operation of the switching device E upon a movement back to the middle position, or from the middle position to a position in which contact 52-55 is closed or from this latter position back to its middle position, is similar to that just described and it will therefore be apparent that any movement of the lever 48 operates finger 58 which thereupon becomes latched, and can be released only if winding 5| is energized and subsequently, de-energized.

If the switching device E has been operated so that the contact 588| is closed, and if the winding 5| is energized so that the contact 84-58 is also closed, it might happen that a quick movement of the lever 49 could be made without releasing the iinger II. This operation is undesirable, and to prevent its occurrence, I have provided the projections 81 on the arm 50. With this arrangement it will be seen that upon any movement of the lever one of the projections I engages the latch II and moves it to the right as shown in Fig. 5. If winding ii is energized, this movement of the latch engages the trigger Cl and positively moves the tip 84 carried by the armature '2 out of engagement with the tip of flnger 58. When this happens the finger 58 immediately returns to a position in which it engages the contact It will be seen therefore that any movement of the lever ensures that the winding II will be de-energlzed. It will be apparent as the description proceeds that this operation of the switching device prevents the simultaneous delivery of two or more codes and therefore makes it impossible for confusion to exist between diflerent codes.

Referring now also to Fig. 1', each panel is provided with a switching device 1! similar to the device illustrated in Figs. 5 and 6. The panels are also each provided with a switching device E similar in all respects to the switching device E except that the switching devices E are device 1'? except that the switching device E are capable of assuming only two positions, contact 54 being omitted and the cam 50 being shaped to accomplish the operation of the associated contact finger it during movement from one extreme position or the other.

In Fig. '1, I have illustrated the cams I! of an associated pair of switching devices E and E. As will appear hereinafter each switching de vice E controls a railway switch, and each switching device 1!? controls the signals governing trafflc over this switch. The apparatus is so arranged that when the switching device lil occupies its middle position (in which contact 52-" is closed) the signals controlled thereby indicate stop and it is desirable to prevent operation of the associated switch controlling switching device E except when the signal controlling switching device Iii occupies such middle position. In order to accomplish this result, the shaft 48 of each switching device is provided with a cam 86, and each panel is provided with a locking slide 68 connecting the two switching devices of the panel to prevent undesirable movements of the switching device E as best shown in Fig. 7. The cam 86 of the device E is provided with a notch 66 to receive a stud 69 on the slide 88 when the switching device occupies its middle position. When the stud 88 of the locking slide 68 enters the notch 66', a second stud 6! is moved out of the path of a projection 88' on the cam 68 of the associated switch controlling switching device E so that under these conditlons'the device E can be operated. If, however, the device It is moved to either extreme position, the stud N is forced out of notch 68", thereby lifting ,the locking slide 68 to a position in which the stud 69'- prevents movement of the device E E of each panel are provided with locking apparatus similar to that shown in Fig. 7, and it is therefore impossible to operate any device E unless the associated device l3 occupies its middle position. Each of the cams it is provided with notches which co-operate with a spring 61 to accurately hold the associated shaft 0 in the positions in which the arm 52 engages one of the corresponding contacts.

The control station is also provided with a The switching devices E andlocking relay L, a motor relay M, and a delay relay K, which for convenience of manufacture, may be constructed similar to the delivery magnets (1 of the coding units a. The control station also comprises a line relay R, a transmitting relay T and a sectionalizing relay S. Certain of the relays just mentioned are utilized in the operation of checking and locking the line c'lrcuit preparatory to delivering a code to the circuit, and before describing the operation of the apparatus located at the control station, I will explain the operation of the checking and locking apparatus.

In Fig. 4, I have illustrated those portions of the apparatus which are involved in the checking and locking functions. It should be noted that the apparatus at station 13 includes a motor relay M and a delay relay K similar to those described in connection with the control stations and the operation of which will be explained hereinafter. For present purposes it is sufllcient to state that when the sectionalizing relay :3 is de-energized and when the motor relay M is energized at the control station, the coding apparatus A! is set into operation to deliver a control code to the line circuit. In similar manner when the motor relay M and the associated sectionalizing relay S at any of the remote stations are both energized, the corresponding coding apparatus is actuated to deliver a code to the line circuit from such station. Each remote station is provided with a transmitting relay T, a sectionalizing relay S, and a line relay R, similar to the corresponding parts at the control station. As shown in Fig. 4, the line circuit which is normally closed through line wires i and 2, includes the winding of the line relay, a back contact ll of the transmitting relay T, and a back contact 'I2|3 of the sectionaiizing relay 8 at each station. This line circuit may be traced from battery 3* at station A, through winding of line relay R back contact 'II of relay T back contact 12-13 of relay 8, line wire I between stations A and B, winding of relay R battery 3 back contact 12-13 of relay S thence through apparatus at succeeding stations similar to that at station B, thence through winding of relay R battery 3 back contact of relay S and line wire 2' back to battery 3*. It will be noted that this line circuit includes a 'line battery, designated by the reference character 3 with a distinguishing exponent, at each station. This particular arrangement is not essential, and the entire line circuit could be supplied with energy from a single battery, as disclosed and claimed in a copending application Serial No. 254,690, filed Feb. 16, 1928, by Lloyd V. Lewis, for Railway tramc controlling apparatus, but by distributing the batteries throughout the. system, thereby placing at each station a battery having sufllcient electromotive force to supply the potential drop through the associated line relay and that portion of the line circuit between the corresponding station and the next station, the potential drop between the line wires at any point is kept at a minimum and it is unnecessary to introduce resistance units at the different stations to compensate for variations in the lengths of line wires between adjacent stations.

Since the line circuit is normally closed, all line relays R are normally energized. The sectionalizing relays S and transmitting relays T are all normally de-energized. Motor relays M and delay relays K are all normally de-energized, and the locking relay L at the control station is normally energized by virtue of a circuit which I will describe hereinafter.

At the control station the sending of a code is initiated by de-energizing the normally energized locking relay L. When this happens, a circuit is completed from terminal B, over front contact ll of relay R wires 18 and '11, winding of sectionalizing relay-S wire 18, back contact 18 of relay K, wire 89, and back contact ll of relay L to terminal C. When this circuit is closed, relay S picks up, and the relay is subsequently held in its energized condition over a circuit which passes from terminal B, over front contact 82-83 of sectionalizing relay 8-, wires 84 and 11, winding of relay 8, wire 18, back contact 19 of relay K wire 83, and back contact 8| of relayL to terminal C. When relay S is energized, the normal line circuit through back contact 12-13 of this relay is opened, and a branch is closed from back contact ll of relay T through front contact 12-14 of relay 8 to line wire 2. By virtue of this branch, a closed circuit is provided for relay It and battery 3 so that relay R remains energized. Another result of the energization of relay S is the closing of a pick-up circuit for the motor relay M this circuit passing from terminal B, over front contact 88 of relay S wires 88 and 81, winding of relay M wire 88, and back contact 8| of relay L to terminal C. Relay M therefore picks up, and is subsequently stuck up over its own front contact 88 and back contact 8i of starting relay L, the stick circuit being apparent from the drawings without tracing it in detail.

When relay M becomes energized, a circuit is closed for transmitting relay T which passes from terminal B, through the winding of relay T thence through the code wheel contacts of the coding apparatus in series and front contact 89 of relay M to terminal C. The code wheel contacts are all normally closed so thatthe circuit just traced is closed and relay T picks up. It will be noted that the opening of back contact 1| of relay T interrupts the circuit for relay RA so that the latter relay becomes tie-energized. When this happens, the delay relay K is energized over back contact 15 of relay R thereby interrupting the circuit for relay S at back contact.19 of relay K'. The sectionalizing relay therefore becomes de-energized, but a snubbing circuit for this relay is now closed from terminal B, through resistance 99, front contact 19 of relay K, wire 18, winding of relay S wires 11 and 84, front contact 82-83 of relay S to terminal 3. As a result of this snubbing circuit a considerable interval of time elapses before the sectionalizing relay releases, and during this interval of time it is impossible for the coding apparatus A to be aperated to deliver a control code to the line circuit. At the conclusion of the holding time of relay S, the relay closes its back contact 85, and when this occurs, since relay M is now energized, current flows over the partial circuit including back contact 85 of relay S and front contact 9| of relay M to the motor of the coding apparatus A as will be described hereinafter. The coding apparatus is thereupon set into operation to operate selected ones of the code wheel contacts. Each time a code wheel contact operates, the transmitting relay T is de-energized, and when this occurs the line circuit is closed to all of the remote stations so that the operation of the coding aprelay to become deenergized, thereby stopping the operation of the motor of coding apparatus AM Since the. line circuit is now completed through the winding of relay it, this relay is continuously energized and relay K becomes deenergized to restore the apparatus to the condition in which it is shown in the drawings. It will be noted that when relay L becomes de-energized to commence the delivery of .a code from the control station, relay S can be energized only if relay R is energized and relay K is de-energlzed. If, however, the line circuit is receiving a code from another station, relay R will follow this code and will hold relay K in its energized position so that if relay L becomes de-energized while the code is being supplied to the line circuit, relay S can not be energized so that the indication is stored until the line circuit is clear.

The delivery of a code from a remote station is initiated by the closing of any one or more of the storing magnet contacts-four of which are shown diagrammatically at each remote station on Fig. 4. The operation of these contacts will be explained below in connection with description of the coding apparatus at the remote stations. In explaining the delivery of a code from station B, I will first assume that the line circuit isclosed as when no code is being supplied to this circuit, and that a storing magnet contact at station .3 becomes closed. Since relay R, is energized, current flows from terminal B, over front contact 15 of relay R wire 92, back contact 93 of relay K wires 94 and 95, winding of relay S wire 99, and a storing magnet contact to terminal C. The sectionalizing relay 8 therefore becomes energized and this operation shifts the line circuit at station B from backcontact 12-13 of relay S to front contact 12-14 of this relay, thereby ineluding back contact ll of transmitting relay T in the line circuit to the control station, and interrupting the line circuit to all more remote stations. With relay S energized, it will be apparent that the line wire I to all stations more remote is disconnected from the apparatus so that it is impossible for codes originating at such more remote stations to interfere with the delivery of codes from station B to the control station. Another result of the energization of the sectionalizing relay S is the energization of the transmitting relay T the circuit for this relay passing from terminal B, over front contact 15 of relay R wire 92, back contact 93 of relay K wires 91 and 98, thence through the code wheel contacts of the coding apparatus A which will be described hereinafter, wire 99, winding of relay T wire I89, and front contact 82-83 of relay S to terminal C. When relay T becomes energized the line circuit to the control station and including the relay R is interrupted at back contact ll of relay T and relay R then becomes de-energized, opening the pickup circuits for relays S and T but relay S is held energized over a holding circuit which extends from terminal B, front contact 85 of relay S back contact 93 of relay K relay S and thence over wire relay K therefore becomes energized. The opening of back contact 83 of relay K interrupts the circuits for relays S and T but a snubbing circuit is now closed through relays S and '1' in series which may be traced from terminal 0, through the storing magnet contact which is now closed, wire ll, winding of relay S wires 95, 94, 01 and 88, code wheel contacts of coding apparatus A in series, wire 88, winding of relay T wire I00, and front contact 82-83 of relay 8 to terminal C. The parts are so constructed that the voltage of self-induction of relay 8 is greater than that of relay T and it follows that current will continue to flow for a time in the same direction in relay 8 but will reverse in relay T therefore relay 'I' holds for only a brief interval when the snubbing circuit just traced is closed, but relay S requires a considerable interval of time to close its back contacts. When relay 'I' releases, the closing of contact ll connects relay R to the portion of the line circuit extending from station B toward the control station A. Although the line circuit was energized when the operations being described were initiated, it may happen that station A or an intermediate station between stations A and B will start the delivery of a code at the same time as station B,

in which case the line circuit at station B will remain open after relay T closes its back contact for a time interval which is greater than the release period of relay 8 so that relay R will remain deenergized until after relay SP releases.

Then when relay R picks up the pickup circuit for relay 3 will be open at back contact 91 of relay K and relay 8 will remain deenergized and the transmitter at station B will remain inactive until relay R becomes steadily energized and relay K releases at the end of the code delivered by the other station. It is apparent, therefore, that station B can continue to transmit only if it succeeds in delivering a relatively short interruption to which relay R responds, to the portion of the line circuit extending to station A. If this condition is fulfilled and relay R picks up before relay 8 releases, a circuit is completed over front contact 15 of relay R wire 92, front contact 93 of relay K wire llll, winding of relay M wire I02, and front contact I of relay 8 to terminal 0. The motor relay MI therefore becomes energized and is subsequently stuck up over a circuit including its own front contact I, and front contact I III of relay 8. The energlzation of the motor relay 1& sets the coding apparatus A into operation, and also completes the holding circuits for relays T and B The holding circuit for relay 'I' may be traced from terminal B, through front contact III of relay H, wire 08. code wheel contacts of coding apparatus A in series, wire ll, winding of relay T wire ill and front contact 82- of relay 8 to terminal C. The holding circuit for relay 8 may be traced from terminal 25, over front contact m of relay M wires 01, SI and as, winding of relay S and wire it through a storing magnet contact to terminal 0. As hereinafter explained in detail, the circuit for motor 1n is closed at contact I when relay M becomes energized, and when the motor commences to operate, contact I! of the governor it closes to energize an auxiliary relay H when relay H becomes energized, the code setting relay or delivery magnet corresponding to the operated storing magnet is energized to release the associated code wheel. The coding apparatus A then operates, with relays M K and S energized, to deliver a code to the line circuit by periodically interrupting the circuit for relay T at a code wheel contact of the coding apparatus. At the conclusion of the code or codes which are stored at station B, all storing magnet contacts become opened and the circuit for relay 8 is then interrupted, so that this relay becomes de-energized to restore the normal line circuit. Relays T and M are then de-energized and the line relay It becomes steadily energized, if the line circuit is clear, to allow the relay K to release.

The checking and locking operations at each remote station are similar to those just described in connection with station-B and it will be plain that no remote station can take command of the line circuit to deliver an indication code unless the line circuit is clear all the way to the control station. When any remote station is delivering a code to the line circuit, the line circuit to all stations more remote is interrupted, and each intermediate station between the sending station and the control station is locked out by the energization of relay K at such station. If the control station is delivering a code to the line circuit, the intermittent operation of the line relays R at the several stations hold the associated relays K in either energized positions, so that the transmitters at all remote stations are locked out and are prevented from delivering indication codes to the line circuit. Should two remote stations attempt to deliver codes to the line circuit at the same time, it is apparent that the station closer to the control station, by theoperation of its sectionalizing relay 8, would look out the more remote station until the closer station has completed delivery of its codes. Finally, if the control station and a remote station attempt to gain control of the line circuit at the same time, the operation of the apparatus at the control station in initially opening the line circuit for a relatively long time interval measured by the release time of relay 8*, locks out the remote station which is attempting to transmit and prevents the delivery of any code to the line circuit from such remote station until the completion of the code from the control station.

In other words, each indication code transmitted to the control station is initiated by a locking element of a particular character, comprising a relatively short line open impulse, and the motor relay M at the remote station is energized to effect transmission of the indication code only if the characteristic initial impulse is properly delivered to the line circuit. Each control code is initiated by a locking element of a diiferent character comprising a relatively long line open impulse which if initiated at the same time prevents the delivery of the locking impulse characteristic of an indication code. Furthermore, each remote station when transmitting delivers a single code element to the more remote stations which is similar to the initial element of a control code. It follows that the control station takes precedence over any remote station and each remote station takes precedence over the more remote stations.

I will now return to a description of the oper- 2,152,890 ation of the apparatus at the control station shown on Figs. 1 and 1'. Locking relay L is controlled in part by a master relay J comprising two windings I55 and I 01 so arranged that 'when winding I 51 is energized, contact I 08-III9 is closed, but when winding I58 is energized, contact III8-I IIIis closed. The relay is constructed in such manner that the contacts oi the relay remain in the positions towhich they were last moved. The locking relay L is also controlled by the switching devices E of all panels at the control station. Under normal conditions contact -55 of each switching device is closed, and current flows from terminal B, over back contact III ot'the delivery magnet d of coding unit 0, wire II2, contact Ill-I III of master relay J, wire II8, resistance II4, wire 5, contact 58-80 of switching device BE, wire II6, contact 58-68 of switching device BE and thence through contacts 58-98 of all switching devices E of all the control panels at the control station and wire H1, and winding of relay L to terminal C. Relay L is therefore normally energized, but it will be 'plain that the operation 01' any of the switching devices E will interrupt the circuit for relay L.

' In describing the operation of the apparatus at the control station in delivering a control code to the line circuit, I will first assume that the operator reverses the switching device BE This operation of the device closes contact 52-55 and also moves finger 58 into engagement with contact 5| in which position the finger 58 is held by latch 59. It will be plainthat this operation of the switching device interrupts the circuit just traced for the locking relay L, so that this relay closes its back contact 8| and initiates the checking and locking operation previously described. After the cycle or operation described in c6nnection with Fig. 4 has been completed, relay S becomes deenergized, and since relay M is then energized, an operating circuit for motor m is closed from terminal B, over back contact of relay 8, wire II8, front contact 9| of relay M wire II9, armature 4 of motor m, and wire I20 to terminal C. .A branch is provided for the circuit just traced from wire II9 through field 5 of motor m, wire I, and a resistance I3 to terminal C. When the circuit just traced is closed, the motor m is set into operation and the speed of this motor is maintained at a constant value by means of a regulator h of the centrifugal type having a contact II shunted across the resistance I3 to decrease the resistance in series with the shunted field 5 when the speed of the motor exceeds a predetermined value. The governor h also controls a contact I2 which is closed at all times when the motor is operating, but which is opened when the motor is at rest.

As soon as the'motor m commences to operate, the contact I2 closes and a circuit is then completed for a selected one of the code selecting relays Q, depending upon the position of the switching device which has been operated. I have assumed that contact 52-55 of device BE is closed, and the code selecting relay BQ is therefore energized over a circuit which may be traced from terminal B, through back contact III of unit 9, wire II2, contact I 09-I I0 of master relay J, wire H3, resistance II4, wire I I5, contact 58-5I of switching device BE wire I22, winding 5I of switching device BE}, wire I23, contact 52-55 of switching device BE, wire I24, winding of code selecting relay BQ, wires I25, I28 and I21, contact I2 operated by governor h of motor m, and wire I 28 to terminal C. I As explained hereinbetore, the energization of a code selecting relay Q connects certain ones of the fixed segments of'the stepping contactor P with selected ones of'the delivery magnets of the coding units a to provide a distinctive code as shown in the drawings. 1 The code which is delivered to the line circuits when the switching device BE is moved to its reverse position, as just described, is made up of six digits having the following impulses, 6-4- 1 as will presently appear. It should also be noted that the circuit, by means 01 which the code selecting relay BQ' is energized, includes the winding 5I of the switching device BE so that the armature of this switching device isnow attracted and the latch 58 is released, but the tip 54' on armature 52 now engages the end or finger 58, and prevents the movement of this finger to its original position until the winding 5| is again de-energized.

Furthermore, since contact 94-58 of switching device BE is now closed, an auxiliary circuit is closed from terminal B, over back contact III 01 coding unit 9, wire II2, winding Illloi' master relay J, wire I29, winding of reset relay 1, wires I80, I8I and I32, contact 54-58 of switching device BE contact '58-8I of switch device BE, wire I22, winding 5|, wire I22, contact 52-55, and thence as before through the winding of relay BQ and contact I-2 of governor h to terminal 0. The current delivered to winding I01 of master relay J over this :circuit, reverses the relay and closes contact loll-I89. Current then flows from terminal B, over back contact I I I of coding unit 9, wire II2, contact I88-I59 of master relay J, wire I34, winding of the operating magnet F of the stepping contactor P, wire I85, and thence through back contacts of the delivery magnents d of all of the coding units g in series except coding unit 0. Since the delivery magnets are all normally de-energized, magnet F now becomes energized. This operation of magnet F moves the pawl M (Fig. 8) one tooth on the ratchet wheel 8|, but does not shift the spider 29 which normally engages the fixed segment 59. When the magnet F becomes energized, however, its front contact I35 becomes closed, and a circuit is then completed for the delivery magnet of the coding unit or from terminal B, over front contact of magnet F, wire I21, contact 29-89 of stepping contactor .P, and thence through the winding of the delivery magnet 11 of coding unit g to terminalC. Since the motor m is now operating, the energization of the delivery magnet of the coding unit 0 to withdraw the latch from the cam I5, allows the code wheel D to rotate, thereby actuating the contact I4 associated therewith to open this contact six times. It will be remembered that the contact I4 of the code wheel D is included in the circuit over which relay T is energized so that each time the contact I4 of code wheel D is opened, relay T becames de-energized to deliver an impulse to the line circuit. When the six impulses comprising the first digit have been delivered to the line circuit by coding unit g, the latch I8 again enters a notch in the cam I5 and prevents further operation of the code wheel. When the delivery magnet became energized to initiate the delivery of the first digit of the code to the line circuit, the back contact I9 of this delivery magnet opened, thereby opening' the circuit previously traced for the operating magnet F, and this magnet therefore became de-energized. As a result, the spider 29 of the stepping contactor P was advanced one step, thereby breaking contact 29-39 and closing contact 29-99. The circuit for the delivery magnet was opened when relay F became de-energized, and the circuit is now held open by the stepping contactor but the coding unit continued to operate because the latch was mechanically held by engagement with the periphery of the cam I5.

As soon as the delivery of the first digit of the code by unit g is completed, the contact I9 of this unit again closes, thereby completing the circuit for magnet F. The contact I95 of this magnet is therefore closed, but the spider 29 is not moved, and current is supplied now to a selected one of the coding units depending upon which of these units is connected with segment 29 of the stepping contactor P. This selection is, of course, controlled by the code selecting relay BQ and under the present conditions, this circuit may be traced from terminal B, over front contact I95 of magnet F, wire I91, contact 29-98 of contactor P, wire I29 to bus bar I39 and thence over wire I40, front contact I of relay BQ, bus bar I42 and wire I49, through the delivery magnet d of unit a to terminal C. The unit 9 is therefore set into operation to open its contact I9 and de-energize the magnet F of the stepping contactor P, thereby advancing this contactor one step. Since the motor m is still operating the energization of the delivery magnet of unit 9 starts the operation of code wheel D and the contact I4 operated by this code wheel then interrupts the circuit for the relay T four times to deliver the second digit of the code, in this case consisting of four impulses, to the line circuit. The remaining digits of the code are delivered to the line circuit in a manner similar to that described in connection with the first two digits of the code, it being noted that the third, fourth, and fifth digits of the'code in this case consisting of two, five and three impulses, respectively, are produced by the corresponding ones of the coding units 0, depending upon the bus bars which are connected together by the energization of the code selecting relay BQ.

At the conclusion of the fifth digit of the code, the spider 29 engages the segment 94 and the next digit of the code is a single impulse delivered by unit 9 In the next position of the stepping contactor P, to which position the spider 29 is moved as soon as the code wheel D starts the delivery of the sixth digit of the code, contact 29-99 is closed. when the contact I9 of the delivery magnet d of coding unit a closes after the 55 conclusion of the sixth digit, the magnet F becomes energized, and current flows from terminal B, over front contact I36 of magnet F, .wire I91, contact 29-43 of. contactor P, and thence through the delivery magnet d of coding 0 unit 0 to terminal C. The front contact of this coding unit is then closed and the back contact opens. The opening of the back contact of unit 9 interrupts the circuit for winding 5I of switching device Bill and the armature of this device 5 is therefore released to break contact 94-59 and permit the finger 55 to return to the position in which it is shown in the drawings. Relay I also becomes de-energized. At the same time the code selecting relay BQ" is de-energized. If no 70 other switching device has been operated, the circuit originally traced for the locking relay L is then completed and the relay becomes energized to de-energize relay M Relay K is also de-energized by the steady energization of the 75 line relay RA.

The closing of front contact III of coding unit 9 completes a circuit from terminal B, over front contact III, wire I44, and winding I95 of master relay J to terminal C. The master relay is then restored to normal so that contact Nil-I09 is opened. When the latch I9 of the coding unit 9 enters the next notch in one cam I5, contact I II is again closed and the circuit first traced for locking relay L through the contact 59-95 of the switching devices E is closed and if all switch- 10 ing devices now occupy their normal positions in which they are shown in the drawings, the locking relay L becomes energized and the apparatus is restored to normal in the manner previously described in connection with Fig. 4. 15

It should be noted that the opening of front contact III of the coding unit at the beginning of the operation of this unit de-energized magnet F, thereby stepping the spider 29 to a position in which contact 29-99 is closed so that 20 the apparatus is now ready to commence the delivery of another code.

If other switching devices E at the control station have been operated during the delivery of the code initiated by switching device BE, the 25 circuit for locking relay L will not be completed when the finger 58 of switching device 18!! returns to its normal position. Instead, the cycle of operations previously described will be repeated with the exception that the code selecting 3o relay corresponding to another switching device E will then be energized to deliver a corresponding code to the line circuit. If a switching device is operated while a code is being delivered from the control station, the code correspond- 35 ing to the switching device will be delivered to the line circuit immediately upon the completion of the code then being delivered and the relays R, T, S, M, and K do not operate to perform the usual checking functions. This 40 checking of the line circuit is, of course unnecessary, because no remote station can take command of the line until the normal line circuit has been re-established after a completion of the code originating at the control station. 45

It will be observed that since the control circuit for the locking relay L which includes the contacts 59-50 of all of the switching devices E traverses these contacts in a definite order, the switching devices will take precedence in this order. That is to say, if devices BE and xiii are both operated at the same time, the device 3E will deliver its code first, because the finger 59 of this device is connected with terminal 13 and when the finger is moved to itsoperated position, energy is disconnected from all subsequent devices in the series at the contact 59-99 of device BE After the code corresponding to the device BE has been completed. the next device in order, in this case, device XE will deliver 60 its code to the line circuit and so on, until all of the devices which have been operated, have delivered their proper codes to the line circuit.

If any switching device is operated to initiate the delivery of its code to the line circuit and is 5 restored to its original position before the corresponding code is completed, the winding ii of such device is immediately de-energized and the undelivered portion of the code is cancelled. It is necessary, however, for the stepping contactor P to have its contact 29-29 closed to commence the delivery of a code. To ensure that this contact always occupies its proper position when a codeis not being delivered to a line circuit, I have provided a reset relay 1 and a code selecting relay JQ controlled thereby. I have already explained how relay 1 is energized when a code is being delivered to the line circuit. Should a switching device be restored to its original position before the completion of the corresponding code, relay I immediately becomes de-energized, and the closing of back contact 65 thereon, completes a circuit for the coding relay IQ, which then picks up to connect the bus bars associated with contacts 65, 36, 31 and 68 of the contactor P with the delivery magnet d of the coding unit 9 The apparatus thereupon operates to finish out the code with digits of one impulse each in order to ensure that the stepping contactor P comes to rest with contact 29-39 closed in order to be prepared for the delivery of another code.

The control codes delivered to the line circuit by the control station through the medium of the apparatus illustrated in Figs. 1' and I", operate the line relays R at all remote stations. As best shown in Fig. 4, each remote station is provided with a plurality of selectors which are selectively responsive to the control codes thus supplied to the line circuit. The selectors at the remote stations are' each designated by the reference character N with a prefix corresponding to the station and a distinguishing exponent. Each time a line relay becomes de-energized an impulse of energy is supplied to each of the associated selectors over back contact 15 of the line relay. It follows, therefore, that the selectors at their station are supplied with impulses in accordance with the control codes delivered to the line circuit.

The selectors may be utilized to control trafiic governing devices in any suitable manner. As shown in Fig. 3, selectors BN BN BN and BN at station B control trailic governing devices associated with a section of railway track a--b. This section is provided with a switch e connected with a siding u. The switch e is operated by a motor 2 comprising an armature I61 and a field I66 and controlled bytwo relays p and p. Eastbound traffic over the switch a is controlled by two signals 20 and 10 located adjacent point a and westbound trafiic by two similar signals w and 10 located adjacent point b. The section ab is also provided with a track circuit comprising a battery 262 connected across the rails adjacent one end of the section, and a track relay connected across the rails adjacent the other end of the section. Associated with the track relay 1; is a slow-acting repeater relay 3 having a circuit including a front contact 2I5 of the track relay 1). The signals w, w", w and w are controlled in part by two relays q and q which are in turn controlled by two of the selectors BN and EN.

As shown in the drawings the section of track a-b is unoccupied. The switch e occupies its normal position, all signals w indicate stop, and all of the relays 12 p, q and q are de-energized. Relays v and y are both energized.

If the operator at the control station wishes to reverse the switch e at station B, he reverses the switching device BE on panel B (Fig. 1). As a result, there is delivered to the line circuita distinctive control code and the parts are so arranged that this code closes the contact of selector BN for a brief interval of time. While this contact is closed a circuit is established for relay p (Fig. 3) which may be traced from terminal B, through wire I46, winding of trip relay t, wire I41, contact of selector BN wires I66 and I49, and winding of relay 1) to terminal C. Relay p therefore becomes energized, and is subsequently held in its energized condition by a stick circuit which passes from terminal B, over contact I50--I6I operated by switch e, wire I56, back contact I54 of relay 12, wire I55, front contact I56 of relay p", wires I51 and I69, and winding of relay p to terminal C. The contact of the selector BN opens after a brief interval of time and the trip relay t is then again de-energized, but relay p is now held closed as long as contact I 50-;I5I is closed. When relay 9 is energized, the motor a is operated to move the switch to its reverse position, the circuit for the motor passing from terminal B, over front contact I66 of track relay 0, wires I59 and I60, front contact I6I of relay p wire I6I, armature I61 of motor 2, wires I62 and I86, front contact I86 of relay p, wires I65 and I66, and field I66 of motor 2 to terminal C. When the switch has attained its full reverse position, contact I50-I5I opens, thereby breaking the stick circuit for relay p and allowing this relay to become de-energized.

If, now, the operator at the control station wishes to restore the switch e at station B to its normal position, he restores the switching device Bl?! to its normal position, whereupon the coding apparatus at the control station, delivers to the line circuit a different code from that which is delivered when the switching device Blli is reversed and this causes the operation of selector RN to close its contact for a brief interval of time. The operation of selector BN completes a circuit from terminal B through wire I46, winding of trip relay t, wire I61, contact of selector BN wires I69 and I10, and winding of relay 1: to terminal C. The contact of selector BN opens after a brief interval to de-energize relay it, but relay 1: remains energized, its stick circuit now being closed from terminal B, over contact I50-I52 operated by switch e, wire "I, back contact I12 of relay p, wire I16, front contact I16 of relay p wires I15 and I10, and winding of relay p to terminal C. When relay 9 is energized, current is supplied to motor 2 to drive the switch e to its normal position. The operating circuit for the motor under these conditions is from terminal B, through front contact I58 of track relay '0, wires I59 and I16, front contact I11 of relay 1), wires I18 and I62, armature. I61 of motor 2, wires I 6| and I19, front contact I60 of relay p wires I6I and I66, and field I66 of motor 2 to terminal C. When the switch has been restored to its full normal position contact I50-I52 opens, thereby de-energizing relay p If the operator at station A wishes to clear the signals governing the switch e, he may do so by proper manipulation of the switching device BE. For example, I will assume that the switch e occupies its normal position, as shown in the drawings, and that the operator moves the device BE to one extreme position, for example, to close contact 52-53 of the switching device. The code then delivered to the line circuit operates the selector BN'- at station B, and current flows from terminal B, through the contact of selector BN wires I 62 and I83, and winding of relay q to terminal C. Relay q is held in its energized position after the opening of the contact of selector BN by a stick circuit which passes from terminal B, through wire I6I, back contact I65 of trip relay t, wire I66, back contact I66 of relay q, wire I89, front contact I90 of relay q wires I9I and I63, and winding of relay q to terminal C.

When 'relay q is energized, signal w is moved to signal passing from terminal B, through front contact I92 of relay v, wires I99 and I94, front contact I99 of relay q, wire I99, contact I9'l-I99 operated by switch e, wire 299, and the operating mechanism of signal w to terminal C. If the switch e occupies its reverse position when relay q is energized, a branch is completed for the circuit just traced from wire I96, over contact I9l-I99 operated by switch e, wire MI, and operating mechanism of signal 112 to terminal C. It will be manifest, from the foregoing that if relay-q is energized, signal 10 or signal 10 indicates proceed, according as switch 6 occupies its normal or its reverse position.

If the switching device BE'on panel B at station A is operated away from its middle position to close contact 52-I5, the control code then supplied to the line circuit operates selector BN at station B and current flows from terminal B, through the contact of selector BN wires 292 and 299, and the winding of relay q to terminal C. After the contact of selector BN opens, a stick circuit holds' relay q in its energized condition, current flowing from terminal B, through wire I94, back contact I99 of trip relay t, wires I99 and I91, back contact 294 of relay q wire 299, front contact 299 of relay q, wires 29! and 299, and winding of relay q to terminal C. When relay q is energized, signal to is operated provided the switch e occupies its normal position, current flowing from terminal B, through front contact I92 of relay 0, wire I99, front contact 299 of relay q, wire 209, contact 2l9-2II operated by switch e, wire 2 l9, and operating mechanism of signal 10 to terminal C. If switch e occupies its reverse position when relay (,1 is energized, a branch is closed for the circuit Just traced from wire 299, through contact 2I9-2I2 operated by switch e, wire 2, operating mechanism of signal w to terminal 0. when relay q is energized, therefore, signal an or signal 10 indicates proceed according as switch e occupies its normal or its reverse position.

It will be observed that back contact I of the trip relay t is included in the stick circuits for both relays q and a, so that any energization of this trip relay will break the stick circuit for either of these relays which happens to be energized, and will therefore restore all of the signals w to stop. But the trip relay t is energized when either of the selectors BN or BN is operated. These two selectors control the switch operating motor z and are responsive to the codes delivered from the switching device BE at the control station. The purpose of this construction is as follows:

Referring again to Figs. 1 and 1', it will be noted that the middle contact 94 of each switching device E is connected directly with the movable contact arm 52 of the associated switching device E With this arrangement it will be plain that if switching device B13. is moved from either extreme position to the middle position, the coding apparatus A will operate to deliver to the line circuit, the code corresponding to the position which the switch controlling switching device E then occupies. That is to say,.as shown in Fig. 1 the switching device BE occupies its normal position so that contact 52-43 is closed. If, now, the switching device HE is operated to one extreme position to close contact 52-45, the selector BN at station B will be operated to pick up relay q as explained hereinbefore. Since the switch e occupies its normal position, signal 10 will then be moved to its proceed position. If,

now, the switching device BE is restored to its middle position so that contact 92- is closed. the coding apparatus is set into operation at the control station to deliver to the line circuit the same code which would be delivered were the switching device BE moved from its reverse to its normal position, and during the delivery of this code, the code selecting relay Btf.) would be energized so as to operate the selector BN at station I. The operation of this selector, woul of course pick up relay 12 Since switch e 00- cupies its normal position, the stick circuit for this relay is open at contact III-I52 operated by the switch e, and the relay p again becomes de-energized without affecting the switch in any way, as soon as the selector BN opens its contact. During the brief interval that the selector BN has its contact closed, however, the trip relay t is energized, thereby opening back contact I95 and interrupting the stick circuit for relay q As a result the relay a becomes de-energized and remains de-energized until selector BN is again operated to close the pick-up circuit for this relay. One advantage of my invention is that this important operation of restoring signals to stop is accomplished without the necessity of a separate and distinct code for this purpose.

In order to inform the operator at the control station concerning the condition of apparatus at the several remote stations, each remote station is provided with apparatus for delivering to the line circuit indication codes for operating selectors at the control station in accordance with the condition of the apparatus at the remote stations. Referring particularly to Figs. 2 and 3, the station B is provided with coding apparatus A similar to that described in the Snavely application Serial No. 254,684 referred to hereinbefore. This coding apparatus has some features in common with the coding apparatus located at the control station, and comprises a motor m driving a shaft I9 which operates a plurality of code wheels each designated by the reference character D with an appropriate distinguishing exponent.

Each of the code wheels D of the coding apparatus A delivers a complete code, however, instead of simply delivering code elements as is the case with the apparatus located at the control station. Each of the code wheels in the apparatus A is controlled by a code setting relay or delivery magnet d similar to the delivery magnet d at the control station, and associated with each such delivery magnet d is a storing magnet 1' having an armature which is normally biased to the right by spring contacts 299 and 294. When the storing magnet is energized, the armature is moved to its left-hand end or attracted position, thereby closing front contact 295 and opening back contact 294. When the parts are in these positions, a latch 296 drops into a position in which the armature is mechanically held in its attracted position. For the purpose of disengaging the latch 299, the latch I9 operated by delivery magnet 11 is provided with a tip which engages an inclined surface of the latch 299 in such manner that when the delivery magnet d is energized, the latch I9 lifts the latch 299 out of engagement with the armature of the storing magnet. It should be observed, however. that when the latch I9 is in the position corresponding to the energized condition of the delivery magnet d, the armature of the storing magnet r is held in its left-hand position by direct engagement of the latch I9 with the armature itself,

so that the front contacts of the storing magnet are held closed, even though the latch 22 is released, and even though the storing magnet may be electrically tie-energized. It should also be pointed out that after the latch II has once been operated to release the cam II, and the motor has rotated the cam away from registration of the latch, the engagement of the latch with the edge of the cam will prevent the return of the latch to its normal position. After the cam has once been released to permit operation of the associated code wheel, the latch l8 ismechanically held in a position in which the front contacts of both the delivery magnet and storing magnet are closed, until the code wheel hasmade a complete revolution to permit the latch to enter another notch in the cam l5. During this operation of the code wheel, a complete code is relivered to the line circuit by periodically energizing relay T in a manner previously described in connection with Fig. 4.

Each of the code wheels is controlled by a storing magnet and a delivery magnet and each code wheel with its associated magnets and contacts may be referred to collectively as a coding unit and for distinguishing these coding-units from the coding units of the apparatus located at the control station, I have identified each of them by the reference character G with a suitable distinguishing exponent.

The storing magnets r of the coding units G at each remote station may be controlled in accordance with the condition of the governing devices at that station in any suitable manner. As shown in Figs. 2 and 3, units G and Gr are controlled in accordance with the condition of the track circuit, and units CF and G are controlled in accordance with the position of switch e at station B. For example, if a train enters section o-b, relay 2; becomes de-energized, thereby de-energlzing relay 1 Relay 1; is slow-acting, however, and an interval 'of time elapses after relay 1: is de-energized during which relay 1 holds its front contacts closed. Din-ing this brief interval of time, an impulse of energy is delivered from terminal B on Fig. 3, through back contact 2|5 of relay v, wire 2|, front contact 2" of relay y, and wire 2|. to the coding apparatus A As seen in Fig. 2 the continuation of this circuit in the coding apparatus passes from wire 2|8, through wire 231, the winding of the storing magnet r of coding unit G wires 238 and 229, back contact 240 of relay H and wire 24l to terminal C. When the storing magnet r of unit G is energized, it is latched in its attracted position by the latch 236 so that the storing magnet holds its front contacts closed after the energizing circuit just traced is interrupted.

When any one of the storing magnets of the coding apparatus A is energized, a circuit is completed for the sectionalizing relay 8 as previously explained in connection with Fig. 4. The operation of relay S initiates the checking and locking functions of the relays T S R, M, and K and if the line circuit is clear, relay M becomes energized at the conclusion of the checking operation. When relay Mbecomes energized, a circuit is closed for the motor m from terminal B, through wire 242, front contact 242 of motor relay M wires 244 and 244", armature 4 of motor m, and wires 245 and 246 to terminal C. This circuit is provided with a branch which passes from wire 244, through field 5 of motor m, wire 24! and resistance I! to wire 246. The motor m drives a governor h, a contact ll of which is shunted across resistance It as explained in connection with coding apparatus A, to maintain constant the speed of the motor m. When the motor m commences to operate, contact I2 is closed, and a circuit is then completed for an auxiliary relay K This circuit may be traced from terminal B, through wire 243, front contact 242 of motor relay M wires 248 and 253, and thence through back contacts 232-233 of all of the delivery magnets 11 in series, wire'254,

winding of relay H wire 255, contact l2 of govemor h, and wires 256 and 246 to terminal C. When relay H becomes energized, the delivery magnet associated with the storing magnet which has its front contacts closed becomes energized. In the present instance, the delivery magnet d of the coding unit G becomes energized over a circuit which may be traced from terminal B, through wire 248, front contact 242 of motor relay M wire 248, front contact 234 of storing magnet r of coding unit 6*, wires 249 and 250. winding of delivery magnet d of coding unit G wires 25l and 252, front contact 240 of relay H and wires 2, 24F and 24| to terminal C. The delivery magnet d therefore becomes energized and releases the latch 236 of the associated storing magnet 1'. Since the .motor m is now operating, the code wheel D is therefore set into operation and the delivery magnet and the storing magnet of the'coding unit G are held in their energized positions until the conclusion of the code which is now delivered by the code wheel D. At the conclusion of this code, latch l8 again enters the notch in the cam I5, thereby preventing further operation of code wheel I) and closing the back contacts of the delivery magnet and the storing magnet of coding unit G When this occurs the circuit for relay H is a in closed, this relay having becomede-energized when the delivery magnet d of coding unit G first became energized. When relay H picks up, if any storing contact in coding apparatus A is closed, the corresponding delivery magnet is energized and another code wheel is operated to deliver the corresponding code to the line circuit. If, however, no other storing contacts in coding apparatus A are closed, the relay S becomes de-energized, thereby restoring the line circuit to normal and causing relays M K H and T to become de-energized.

As explained in detail in my previous application Serial No. 254,684, it is impossible for more contact 2l5 of. relay v, wires 2|! and 220, back contact 22I of relay 1!, and wire 222 to the coding apparatus A and thence on Fig. 4, through wire 258, winding of storing magnet r of coding unit (3 wires 260 and 239, back contact 240 of relay H and wire 2 to terminal C. This circuit is closed only for a brief interval during the time required by relay y to become energized after relay v has picked up following the departure of a train from section a-b.

In similar manner, the coding units G and G are controlled in accordance with the position of switch e. For example, I will assume that the switch e has been moved to its reverse position by energizing relay p, as described hereinafter. When the switch attains its full reverse position a circuit is completed from terminal B on Fig. 3, through contact 222-22l, wire 222, front contact 221 of relay 9', and wire 222 to the coding apparatus A, and from wire 222 on Fig. 4 to the storing magnet r of coding unit as will be plain from the drawings without tracing the circult in detail. The storing magnet r of coding unit G is energized when switch e of station B is restored to its normal position, the circuit for accomplishing this result, passing from terminal B on Fig. 3, through contact 222-424 operated by switch e, wire 22!, front contact 222 of relay p and wire 22! and thence through the storing magnet r of coding unit G, as will be apparent from an inspection of Fig. 2.

when more storing magnets than one are energized simultaneously the corresponding codes are delivered to the line circuit consecutively in the order determined by the circuits for the delivery magnets. After a storing magnet is energized, however, the latch 22' holds the armature of the magnet in its attracted position until the corresponding code has been sent out. As shown in the drawings, unit G delivers its code before unit G". If therefore, a train enters section w-b at station B, and then leaves the section, the storing magnets of units G and G will both be energized. If the train again enters the section before the codes have been delivered, G will deliver its code first, and G will then deliver its code. The result will be that the code corresponding to an unoccupied track section is the last code sent out, although the section is now occupied. In order to prevent this condition, I provide a latch magnet 2li1 connected in parallel with the storing magnet r of unit G and arranged when energized to lift the latch 226 of storing magnet r of unit G. With this arrangement it will be seen that if the storing magnet of unit (3 is latched up, and if the storing magnet of unit G then becomes energized, the energization of latch magnet 251 will trip the storin magnet of unit (3. It follows that if unit G is the last to have its storing magnet energized, this unit, but not unit (3 will deliver its code to the line as soon as the line circuit is clear.

For similar reasons I have provided a latch magnet 25! for releasing the storing magnet of unit G if the storing magnet of unit (3 is energized. It is therefore assured that the code delivered to the line circuit at any time from a station represents the condition then occupied by the apparatus at the station at that time.

Located at the control station and associated with each of the panels are selectors which are selectively responsive to the codes delivered to the line circuit by the coding apparatus located at each remote station. Referring again to Figs. 1' and 1", it will be seen that the selectors Bn Bn, etc., on panel B and selectors xn Xn, etc., on panel X are supplied in parallel with current over back contact of relay 1i. when this relay becomes de-energized. It will be remembered that the relay R follows the codes delivered to the line circuit by any remote station, and it follows that the selectors at the control stations are supplied with impulses of energy in accordance with the code delivered from the remote stations. The selectors on each panel control two indication relays each similar to the master relay J, and each designated by the reference character 1' with a prefix corresponding to the panel and a distinguishing exponent. Referring particularly to panel B, I will assume that the selector B1: is operated by the code delivered by coding unit G at station B. when a train enters section ab at station B, therefore, the selector Bn at the control station closes its contact for an instant, and when this occurs current is supplied to one winding of relay Bi over a circuit which passes from terminal B, through a normal contact of a manually operable circuit controller BW, the contact of selector Bn and winding 222 of relay B1 to terminal 0. The relay B1! is then energized to close contact 283-4 and current is supplied to an indication lamp 2" over a circuit which will be apparent from the drawings. The contacts of the indication relays 1 remain in the positions to which they were last moved, so that this indication lamp 2" remains energized after the contact of the selector B1: is opened, to indicate to the operator at the control station that section 0-!) at station B is occupied by a train.

It is sometimes desirable to give an audible indication as well as a visual indication of the entrance of a train into a section of track controlled from station A. In order to accomplish this result the circuit controller BW on panel B may be reversed, and the winding of a relay 281 is then inserted in the circuit controller by the contact of selector Bn for reversing relay BP. The relay 261 will therefore be energized for a brief interval of time when selector Bn is operated. When relay 281 is energized, an audible signal, such for example, as a bell 282 is operated to inform the operator that a train has entered a track section. The relay 261 may be controlled by the selector of any panel by operating the appropriate circuit controller W.

The selector Bn' at panel B is arranged to respond to the code from unit (3' at station B, and when this selector closes its contact current is supplied to winding 22! of relay B1 over a circuit which will be apparent from the drawings. When this winding is energized, contact 282-210 is closed to light lamp 2", thereby informing the operator that section a-b at station B is now unoccupied. In similar manner, the selectors Bn and En are responsive to the codes delivered from coding units G and G at station B. When selector B12 is operated winding 212 of relay BP is operated to close contact 212214 of this relay and light lamp 215. It follows that when lamp 215 is lighted, the operator knows that the switch e at station B occupies its normal position. When selector Bu is operated, however, winding 216 of relay 133i is energized and contact 214-211 of this relay is then closed to energize lamp 21., thereby informing the operator that switch e at station B occupies its reverse position. Each of the remaining panels at the control station is provided with apparatus similar to that just described in connection with panel B, and the operation of the apparatus will be apparent from the foregoing description.

In addition to the visual and audible indication concerning the condition of apparatus at remote stations, it is sometimes desirable to have a permanent record of certain operations, as for example, of the entrance of trains into the several track sections at the remote stations. For this purpose I provide a graphic train recorder of the usual and standard form comprising a plurality of magnets each designated by the reference character 21! with an appropriate distinguishing exponent, one of these magnets being provided for each panel. Each magnet 21! is arranged to be energized when the associated relay 1 is actuated to close its contact 288-284. This operation takes place, it will be remembered, when a train enters the corresponding section at the remote station and each magnet 218 is therefore energized when the corresponding section is occupied. Each of the magnets 218 may control a pen on the train recorder in accordance with the usual practice.

It is sometimes desirable for the operator in charge of the control station to be informed when a code is supplied to the line circuit from either the control station or remote station. This may be accomplished by means of the two lamps 288 and 281 which are controlled in part by a relay 282. The circuit for relay 282 may be traced from terminal B, through the winding of relay 282, wire 288, and front contact 88 of relay M to terminal 0. Relay 282 is therefore de-energized when a code is being received from a remote station, and under these conditions, each operation of relay R in response to this code, supplies energy to lamp 280 over back contact 215 of relay R and back contact 284 of relay 282. The lamp 288 therefore flashes intermittently to follow the indication code being received from a remote station. When a control code isbeing delivered to the line circuit from station A, however, relay M is then energized and relay 282 is also energized so that front contact 284 of this relay is closed. Under these conditions, the intermittent operation of the relay R, as a result of the control code being delivered to the line circuit, lights lamp 281 intermittently to follow this control code.

In describing my invention, I have illustrated only two panels at the control station but this particular number is not essential. In this connection, it should be pointed out that for any number of panels at the control station with their associated switching devices E, no additional equipment in the coding apparatus A is necessary, the coding units a being operated selectively to combine the various code elements to produce complete codes in accordance with the connections of the contacts of the code selecting relays Q. It should also be particularly mentioned that the tramc governing devices at the remote stations may be controlled by selectors in any suitable manner and that the arrangement of apparatus shown in Fig. 3 is by way of illustration only, and should'not be construed to limit. my invention in any particular.

Although I have herein shown and described only one form of remote controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention. 8

Having thus described my invention, what I claim is:

1. Remote controlling apparatus comprising a normally closed line circuit connecting a plurality of stations and including in series a line relay at each station, a code transmitting contact at each station, and means at each station eflective only if the associated line relay is energized for at times shunting said line circuit at said station through the associated line relay and code transmitting contact and for opening said line circuit beyond said station.

2. Remote controlling apparatus comprising a normally closed line circuit connecting a plurality of stations and including in series a line energization of said line relay to re-close said cod'e transmitting contact, and means operating if said line relay subsequently picks up to operate said contact to impress a code upon at least a portion of said line circuit.

3. Remote controlling apparatus comprising a normally closed line circuit extending from a control station to a plurality of remote stations and including in series a line relay at each station, a code transmitting contact at each station, means for each station effective if the associated line relay is energized for at times shunting said line circuit at said station through the associated line relay and transmitting contact and for opening the portion of the line circuit extending to all stations more remote from the control station, means for subsequently operating said transmitting contact to deliver a code to the remaining portion of said line circuit if and only if said remaining portion is closed to said control station, and means operating upon the completion of said code to restore the normal line circuit.

4. Remote controlling apparatus comprising a normally closed line circuit extending from a control station to a plurality of remote stations and including in series a line relay at each station, a delay relay for each remote station arranged to be energized when the corresponding line relay is de-energized, a code transmitting contact at each station, means for each station eifective only if the associated line relay is energized and the associated delay relay is released for at times shunting said line circuit at said station through the associated transmitting contact and for opening the portion of the line circuit extending to all stations more remote from the control station, means for subsequently operating said transmitting contact to deliver a code to the remaining portion of the line circuit provided said remaining portion is closed to the control station, and means operating upon the completion of such code to restore the normal line circuit.

5. Remote controlling apparatus comprising a normally closed line circuit extending from a control station to a plurality of remote stations and including in series a line relay at each station, storing contacts at each remote station, means operating when a storing contact is closed at any remote station to deliver a code to the portion of the line circuit between such remote station and the control station and including the line relay at such control station, means effective when any station is delivering a code to the line circuit to open the portion of the line circuit extending to all stations more remote from the control station, and means for preventing the delivery of code from each remote station until the associated line relay is energized and the portion of the line circuit between such station and the control station is closed.

6. Remote controlling apparatus comprising a normally closed line circuit extending from a control station to a plurality of remote stations and including in series a line relay at each station, 

